Triazole anti-fungal compounds, such as ketoconazole, itraconazole, and fluconazole are known and have been the subject of scientific study, pharmaceutical development, and medical use. Although compounds in this class often exhibit antifungal activity, they differ in terms of efficacy and usefulness in different types of pharmaceutical formulations and treatments. Efinaconazole (CAS registry number 164650-44-6) is a triazole that has demonstrated activity in the treatment of onychomycosis. Formulations useful for the topical delivery of efinaconazole in the treatment of onychomycosis and other triazole antifungal drugs have been described in, e.g., U.S. Pat. No. 8,486,978. Some formulations containing triazole active ingredients exhibit varying degrees of instability during storage. Certain formulations are known to discolor within storage periods as short as one or two days, resulting in composition colors ranging from yellow to deep red or brown. Such discoloration can discourage the prescribed use of the compositions by patients who are reluctant to self-administer the discolored compositions. Stabilized formulations of triazoles such as efinaconazole are therefore needed. The present invention addresses this need.